Mineral water is water that has either naturally or artificially added minerals. Many forms are also carbonated, which may also be the result of natural processes, although this is not required. Technically, it is defined by its having over 250 parts per million (ppm) of a mineral substance.
Most water has to be processed to reduce its mineral content, along with unwanted bacteria or chemicals. Mineral water, on the other hand, is usually obtained from a water source rich in some kind of mineral thought to be beneficial to the health. As water sits in contact with minerals, they are slowly dissolved into it.
To determine whether water can be included in this category, the contents of trace minerals in the evaporation of 0.25 gallons (about 1 liter) of water must be examined. Most mineral water contains more than one trace mineral in greater or lesser values. The various mineral components vary widely, but might include iron, magnesium, calcium, or zinc, a very short list of the various chemical compounds.
Perrier, for example, is a sparkling water that contains calcium, magnesium, sodium, potassium, chloride, sulphate, fluoride and nitrate. These occur in varying amounts with the highest mineral content, aside from bicarbonate, being calcium. In 0.25 gallon (1 liter), there is about 0.1 ounce (2.8 g) of calcium.
Mineral water has often been thought of as healthy to bathe in as well as to drink. Abano Terme near Venice is a naturally occurring hot springs used by the ancient Romans, and still quite popular today. Water in these hot springs includes various sodium compounds. It is doubtful that the Romans actually bathed directly in the springs, which average 188.6°F (87°C).
Abano Terme remains a popular tourist location, with many people bathing in its pools. Italy has many other hot and mineral springs, and it commercially produces the most bottled mineral water brands, an impressive 585. This is over four times as many brands as are produced in the US.
There are naturally occurring areas of mineral water on all the continents, but not all are equally beneficial. Some minerals are not considered healthy, even in trace amounts. The practice of drinking this water for the health still remains hugely popular, although some countries, like the US, don’t allow companies to sell it by promoting the potential health benefits.
Some spas market this water for health purposes, either to drink or to bathe in or both. Practices differ depending upon the availability of the source waters and their mineral contents. As well, some tap water in certain countries is high enough in mineral content to be called mineral water. Experts cite Zurich as having some of the best tasting still waters available directly from the tap.